But WhatsApp's founders turned down Google because they believed the only reason Page was bidding on WhatsApp was to keep it out of Facebook's hands.

Efrati and Lessin say that days before WhatsApp closed its deal with Facebook, Page made a pitch: Come to Google. You'll be able to keep the company independent. You're a threat to Facebook.

That pitch wasn't good enough. WhatsApp decided to go with Facebook.

When Page heard that WhatsApp wasn't interested, he started talking to WhatsApp investor Sequoia. He made it clear that he would outbid Facebook.

It was all for naught. The WhatsApp guys went to Facebook. They thought that Facebook had a better grasp on what they were doing. And, apparently, they felt Page was only interested in WhatsApp as a way to hurt Facebook.

For what it's worth, a source at Google told Efrati and Lessin that WhatsApp misunderstood Page. Page was merely encouraging WhatsApp to remain independent.